In general terms, hyperandrogenism is any clinical or laboratory evidence of an excess of androgens in women. The most frequent clinical evidence of hyperandrogenism in women of childbearing age is hirsutism or acne, with or without anovulation symptoms—such as amenorrhoea or dysfunctional uterine bleeding.
There may be five different causes of hyperandrogenism in women of childbearing potential:                polycystic ovary syndrome;        idiopathic hirsutism;        enzyme deficiencies in the synthesis of steroid hormones;        androgen-secreting tumours;        other endocrine disorders such as Cushing's syndrome, etc.Nevertheless, most women with hyperandrogenism symptoms suffer from polycystic ovary syndrome (80%).        
Polycystic ovary syndrome (or PCOS, also called Stein Leventhal syndrome) is a complex metabolic disorder that may lead to changes in the menstrual cycle, cysts in the ovaries, trouble getting pregnant and other health problems. PCOS is the reproductive and hormonal problem that most frequently affects females of reproductive age. It is estimated that approximately 5% of females suffer from this disorder.
According to the American Society for Reproductive Medicine, PCOS is defined by the presence of any two of the following characteristics:                lack of ovulation over a long period;        high levels of androgens (hyperandrogenism);        a large amount of small cysts in the ovaries.        
The signs and symptoms of PCOS are related to hyperandrogenism and may include:                hirsutism, acne and hair loss;        excess weight or obesity, especially in waist and abdomen;        irregular, sporadic or lack of menstrual periods;        larger and/or polycystic ovaries;        infertility.        
Also, females with PCOS are exposed to a higher risk of developing certain health problems, including:                metabolic syndrome: disorder with several components, amongst which are type 2 diabetes or insulin resistance, high cholesterol levels, high blood pressure (especially around waist and abdomen), high levels of C-reactive protein and high levels of blood coagulation factors;        excessive thickening of the endometrial lining, abundant or irregular bleeding and endometrial cancer.        
PCOS therefore has an important effect on the health system and is a matter of concern for the women who suffer from it.
The pharmacological treatment for hyperandrogenism seeks to correct the associated symptoms by reducing androgen serum levels and/or their peripheral action. This treatment must be maintained for a long time since satisfactory clinical effects usually take months to appear.
Certain drugs approved for the treatment of type 2 diabetes, known as insulin-sensitising agents, have proven to be beneficial in patients with PCOS when are administered by oral route. In this case, the insulin-sensitising agents exert systemic effects that include, among others, the decrease of the body's resistance to insulin by improving the sensitivity of peripheral tissues to said hormone, which finally results in decreased circulating insulin levels and, in parallel, in significantly reduced circulating androgen levels.
Metformin (N,N-dimethylimidodicarbonimidic diamide, Glucophage®), a biguanide-type insulin-sensitising agent, is available for PCOS treatment by oral route. It reduces the clinical signs of hyperandrogenism and improves menstrual irregularities. If metformin alone does not restore ovulation, it may improve a woman's response to pharmaceutical products in fertility treatments. The usual oral dose lies between 500 and 2500 mg/day.
Rosiglitazone (Avandia®) and Pioglitazone (Actos®), belonging to the group of thiazolidindione insulin-sensitising agents, are also available in the United States for PCOS treatment by oral route. Thiazolidindiones have demonstrated reducing hyperandrogenism and restoring ovulation in some patients. The recommended oral dose is between 4 to 8 mg/day for rosiglitazone and between 15 and 30 mg/day for pioglitazone.